Norton Toolroom Wheel, Series: 32A, 3 in Wheel Dia, 1-1/4 in Wheel Thickness, 3/4 in Center Hole, 60, Grade: Medium, Aluminum Oxide Abrasive, Wheel Type Number: Type 11, 7640 rpm Maximum, K Wheel Hardness, Vitrified Bond, Applicable Materials: 400 Series Stainless, Hard Carbon Steels, Soft Carbon Steels, Tool Steels, Aluminum, Cast Iron, Ductile Iron and Gray Iron, Purple Wheel, 1/4 in Face Width, Cup Wheel Shape